Posted by Keith in t [108.162.246.106] on Monday, September 06, 2021 at 18:23:40 :
In Reply to: '48 B1PW carb. help needed posted by Dickie in Southwest Va. [172.70.134.91] on Monday, September 06, 2021 at 17:39:30 :
The pump length will not affect the idle mixture. It only gives a squirt of gas when you accelerate so it will not stumble.
Two things you need to do.
Check the float level. You put in a new needle valve and seat so it needs to be checked and adjusted.
You need to adjust the idle mixture screw. I assume the kit had a new one that you installed. Adjust it for the highest idle. Screw it in slowly until the engine rpm starts to drop the back it out a 1/2 turn or a little more. If you back the screw out too much the rpms will drop again because it’s too rich. Find the sweet spot in the middle.
You can use a vacuum gauge to help you adjust your carb. See the following link. https://www.motortrend.com/how-to/45638/